fix supervisor's zero-gas behaviour

app/ante/ante.go

@@ -36,8 +36,8 @@ func NewAnteHandler(options HandlerOptions) (sdk.AnteHandler, error) {
 
 	anteDecorators := []sdk.AnteDecorator{
 		ante.NewSetUpContextDecorator(), // outermost AnteDecorator. SetUpContext must be called first
-		circuitante.NewCircuitBreakerDecorator(options.CircuitKeeper),
 		NewZeroGasTxDecorator(options.AccountKeeper, options.ScorumKeeper),
+		circuitante.NewCircuitBreakerDecorator(options.CircuitKeeper),
 		NewTrackGasConsumedDecorator(options.AccountKeeper, options.BankKeeper, options.ScorumKeeper),
 		ante.NewExtensionOptionsDecorator(options.ExtensionOptionChecker),
 		ante.NewValidateBasicDecorator(),

app/ante/deduct_fee.go

@@ -3,10 +3,7 @@ package ante
 import (
 	"math"
 
-	errorsmod "cosmossdk.io/errors"
-
 	sdk "github.com/cosmos/cosmos-sdk/types"
-	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	"github.com/cosmos/cosmos-sdk/x/auth/ante"
 	"github.com/cosmos/cosmos-sdk/x/auth/types"
 )
@@ -25,12 +22,7 @@ func NewDeductFeeDecorator(ak ante.AccountKeeper, bk types.BankKeeper, fk ante.F
 }
 
 func (dfd DeductFeeDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error) {
-	feeTx, ok := tx.(sdk.FeeTx)
-	if !ok {
-		return ctx, errorsmod.Wrap(sdkerrors.ErrTxDecode, "Tx must be a FeeTx")
-	}
-
-	if feeTx.GetGas() == 0 {
+	if _, ok := ctx.GasMeter().(*zeroGasMeter); ok {
 		// allow gas-free and fee-free transactions
 		return next(ctx.WithPriority(math.MaxInt64), tx, simulate)
 	}

app/ante/zero-gas.go

@@ -1,7 +1,6 @@
 package ante
 
 import (
-	"fmt"
 	"math"
 
 	"github.com/cosmos/cosmos-sdk/x/auth/ante"
@@ -43,16 +42,18 @@ func (d ZeroGasTxDecorator) AnteHandle(
 		return ctx, err
 	}
 
+	zeroGasCtx := ctx.WithGasMeter(NewZeroGasMeter())
+
 	for _, signer := range signers {
-		v, err := ante.GetSignerAcc(ctx, d.ak, signer)
+		v, err := ante.GetSignerAcc(zeroGasCtx, d.ak, signer)
 		if err != nil {
 			return ctx, err
 		}
 
-		if d.sk.IsSupervisor(ctx.WithGasMeter(NewFixedGasMeter(0, ctx.GasMeter().Limit())), v.GetAddress().String()) {
+		if d.sk.IsSupervisor(zeroGasCtx, v.GetAddress().String()) {
 			return next(
 				ctx.
-					WithGasMeter(NewFixedGasMeter(0, ctx.GasMeter().Limit())).
+					WithGasMeter(NewZeroGasMeter()).
 					WithMinGasPrices(sdk.NewDecCoins()),
 				tx,
 				simulate,
@@ -63,52 +64,43 @@ func (d ZeroGasTxDecorator) AnteHandle(
 	return next(ctx, tx, simulate)
 }
 
-type fixedGasMeter struct {
-	limit    storetypes.Gas
-	consumed storetypes.Gas
-}
+type zeroGasMeter struct{}
 
-// NewFixedGasMeter returns a reference to a new basicGasMeter.
-func NewFixedGasMeter(consumed, limit storetypes.Gas) storetypes.GasMeter {
-	return &fixedGasMeter{
-		limit:    limit,
-		consumed: consumed,
-	}
+// NewZeroGasMeter returns a reference to a new basicGasMeter.
+func NewZeroGasMeter() storetypes.GasMeter {
+	return &zeroGasMeter{}
 }
 
-func (g *fixedGasMeter) GasConsumed() storetypes.Gas {
-	return g.consumed
+func (g *zeroGasMeter) GasConsumed() storetypes.Gas {
+	return 0
 }
 
-func (g *fixedGasMeter) Limit() storetypes.Gas {
-	return g.limit
+func (g *zeroGasMeter) Limit() storetypes.Gas {
+	return 0
 }
 
-func (g *fixedGasMeter) GasRemaining() storetypes.Gas {
+func (g *zeroGasMeter) GasRemaining() storetypes.Gas {
 	return math.MaxUint64
 }
 
-func (g *fixedGasMeter) GasConsumedToLimit() storetypes.Gas {
-	if g.IsPastLimit() {
-		return g.limit
-	}
-	return g.consumed
+func (g *zeroGasMeter) GasConsumedToLimit() storetypes.Gas {
+	return 0
 }
 
-func (g *fixedGasMeter) ConsumeGas(_ storetypes.Gas, _ string) {
+func (g *zeroGasMeter) ConsumeGas(_ storetypes.Gas, _ string) {
 }
 
-func (g *fixedGasMeter) RefundGas(_ storetypes.Gas, _ string) {
+func (g *zeroGasMeter) RefundGas(_ storetypes.Gas, _ string) {
 }
 
-func (g *fixedGasMeter) IsPastLimit() bool {
-	return g.consumed > g.limit
+func (g *zeroGasMeter) IsPastLimit() bool {
+	return false
 }
 
-func (g *fixedGasMeter) IsOutOfGas() bool {
-	return g.consumed >= g.limit
+func (g *zeroGasMeter) IsOutOfGas() bool {
+	return false
 }
 
-func (g *fixedGasMeter) String() string {
-	return fmt.Sprintf("FixedGasMeter:\n  consumed: %d", g.consumed)
+func (g *zeroGasMeter) String() string {
+	return "ZerGasMeter:\n  consumed: 0"
 }